The purpose of the study is to investigate the effect of chronic oral administration of the bicarbonate salts of sodium and potassium on external calcium and phosphorus balance and biochemical markers of bone turnover in women. The study will be carried out in postmenopausal women--a high-risk group for osteoporosis. ALTHOUGH THIS STUDY UTILIZED NO VISITS OR INPATIENT DAYS DURING THE GRANT YEAR BEING REPORTED, A RECENT PUBLICATION RESULTED FROM THIS STUDY.